Go at Google: Language Design in the Service of Software Engineering is an article version of a Rob Pike keynote on, well, let me just quote:

The Go programming language was conceived in late 2007 as an answer to some of the problems we were seeing developing software infrastructure at Google. [...]

Go was designed and developed to make working in this environment more productive. [...]

The article then discusses what this means and how various aspects of Go's design were consciously shaped by a number of pragmatic software engineering issues in building large software across large(r) teams. I find it really interesting reading (and I keep referring to it and having to re-find it, so it's clearly time to put this somewhere more obvious).